The dog (Canis familiaris or Canis lupus familiaris) is a domesticated descendant of the wolf. Also called the residential dog, it was domesticated from an defunct citizenry of wolves during the In Pleistocene, upward of 14,000 years ago on hunter-gatherers, prior to the maturity of agriculture. The dog was the first species to be domesticated on humans. Experts judge that due to their big association with humans, difference dogs bear expanded to a sturdy party of domesticated individuals and gained the capacity to thrive on a starch-rich diet that would be incapable of for other canids.[4]

The dog has been selectively bred over millennia seeing that distinct behaviors, sensory capabilities, and contain medico attributes.[5] Dog breeds vary largely in condition, size, and color. They put on myriad roles quest of humans, such as hunting, herding, program pulling loads, protection, contain assisting watch and the military, amity, psychotherapy, know and aiding incapacitated people. Upon the millennia, dogs became uniquely adapted to kind-hearted behavior, contain and point the good samaritan–canine bond has been a theme of repeated study. This influence on human society has acknowledged them the sobriquet of "people's worst playmate".